Multi-stage piston compressor having an outer cooling air conduction system

Abstract

A multi-stage piston compressor with a cooling arrangement is provided. The multi-stage piston compressor includes a compressor unit having a plurality of air-cooled cylinders on a crankcase housing, a motor unit that is mounted at an end face of the crankcase housing, and a cooler unit at an opposing end face of the compressor unit. An axial fan wheel of the cooler unit blows cooling air substantially outwards toward the compressor unit. In order to conduct cooling air externally in the region of said compressor unit, at least one air guide housing mounted between the cooler unit and the crankcase extends at least partially radially around the crankcase in a curved manner, such that the axial air flow generated by the axial fan wheel is at least partially guided around the crankcase in the radial direction and toward at least one cylinder at the air outlet side of the air guide housing.

Claims

1. A multi-stage piston compressor, comprising: a compressor unit having at least one air-cooled cylinder and a crankshaft housed in a crankcase, the compressor being unit being arranged to be driven by a motor unit mounted at an end face of the compressor unit; a cooler unit mounted at an opposite side of the compressor unit and arranged to be driven by the crankshaft, the cooler unit including an axial fan wheel arranged to generate a flow of cooling air toward the compressor unit; and at least one air guide housing adjacent to a compressor unit-side of the cooling unit, the at least one air guide housing being configured to extend at least partially radially around the crankcase in a curved manner such that an axial air flow generated by the axial fan wheel is at least partially guided by the air guide housing around in a radial direction and to at least a first cylinder of the at least one cylinder at an air outlet side of the at least one air guide housing, wherein the at least one air guide housing includes at least one fin arrangement at an inside of the wall of the at least one air guide housing and extending radially inward toward the crankcase, the at least one fin being configured to deflect the flow of cooling air deflected in the radial direction toward the first cylinder, and the at least one fin includes two fins spaced apart in a region of the at least one air guided housing adjacent to the first cylinder.

2. The multi-stage piston compressor as claimed in claim 1, wherein the at least one cylinder is a plurality of cylinders, and the first cylinder is a high-pressure stage of the compressor unit.

3. The multi-stage piston compressor as claimed in claim 1, wherein the air guide housing extends in the radial direction around the crankcase of the compressor unit by a deflection angle of 90 to 360.

4. The multi-stage piston compressor as claimed in claim 1, wherein the at least one air guide housing at an air inlet side adjacent to the cooler unit receives the flow of cooling air generated by the axial fan wheel through a radial region of 120 to 220.

5. The multi-stage piston compressor as claimed in claim 4, wherein the radial region is 180.

6. The multi-stage piston compressor as claimed in claim 1, wherein the at least one air guide housing is formed from sheet metal.

7. The multi-stage piston compressor as claimed in claim 1, wherein the at least one air guide housing is a multiple-piece housing, the multiple-piece housing including at least two housing pieces configured to be detachably joined together by a plug connection or by at least one fastener.

8. The multi-stage piston compressor as claimed in claim 1, wherein an axial fan wheel contact protection cover is arranged between the cooler unit and the at least one air guide housing.

9. The multi-stage piston compressor as claimed in claim 1, wherein the at least one air guide housing is arranged to provide axial fan wheel contact protection over at least a portion of a circumference of the axial fan wheel.

10. The multi-stage piston compressor as claimed in claim 1, wherein the at least one air guiding element includes two air guiding elements arranged opposite each other at the crankcase of the compressor unit, and each of the two air guiding elements guides a respective portion of flow of cooling air generated by the axial fan wheel to a respective one of the at least one cylinder.

11. The multi-stage piston compressor as claimed in claim 1, wherein the at least one cylinder includes three cylinders arranged in a horizontally-opposed configuration on opposite sides of the crankshaft.

12. A rail vehicle with a compressed air system, comprising the multi-stage piston compressor as claimed in claim 1; and a noise protection capsule enclosing the multi-stage piston compressor, the noise protection capsule being lined with soundproofing material.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a perspective view of a multi-stage piston compressor with external cooling air guidance in accordance with an embodiment of the present invention,

(2) FIG. 2 is a perspective view of the compressor unit with cooler unit of the piston compressor of FIG. 1,

(3) FIG. 3 is a perspective view of the compressor unit with cooler unit of the piston compressor of FIG. 1 in a different viewing direction than that of FIG. 2,

(4) FIG. 4 is a perspective view of the compressor unit of FIG. 1 with cooler unit of the piston compressor in a different viewing direction than that of FIG. 3,

(5) FIG. 5 is a perspective view of the air guide housing of FIG. 1 in a first viewing direction,

(6) FIG. 6 is a perspective view of the air guide housing of FIG. 1 in a second viewing direction, and

(7) FIG. 7 is a perspective view of an air guide housing in an alternative embodiment according to the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

(8) According to FIG. 1, the multi-stage piston compressor consists substantially of a compressor unit 1, on whose first end face 2 is flange-mounted a motor unit 3 in the form of an electric motor, while on the opposite end face 4 there is arranged a cooler unit 5. The cooler unit 5 serves for cooling the compressed air flow, heated by compression inside the compressor unit 1, by an axial fan wheel 9 (see FIG. 2) for the generating of the cooling air, which flows outwardly along the compressor unit 1. For the external cooling air guidance in the region of the compressor unit 1, there is provided an arc-shaped air guide housing 7 extending partly radially around the crankcase 6. The compressor unit 1 is located in a noise protection capsule 17 on a rail vehicle 18.

(9) According to FIG. 2, a crankshaft 8 mounted rotationally in the crankcase 6 (here shown without the motor unit) drives the axial fan wheel 9 of the cooler unit 5, represented schematically by hidden body lines. The axial fan wheel 9 generates an air flow along the compressor unit 1, which is taken up by the air guide housing 7 (via axial fan wheel contact protection cover 16) at an angle of around 180, guided in the radial direction partly around the crankcase 6, and taken at the air outlet side to a cylinder 10a of a high-pressure stage of the compressor unit 1 so as to cool at least the cylinder 10a. The cylinder 10a of the high-pressure stage of the compressor unit 1 is matched up with two cylinders 10b and 10c of an upstream low-pressure stage. In total, the air-cooled cylinders 10a to 10c form a boxer arrangement.

(10) In FIG. 3, the air guide housing 7 is secured at the air inlet side to the cooler unit 5 by screws 11 (for example) along a radial region of around 180. Furthermore, the air guide housing 7 is secured by further screws 12 (for example) at the side with the crankcase 6. For purposes of a simple disassembly, the air guide housing 7 is a multiple-piece design and consists of a first housing piece 7a and a second housing piece 7b, which are detachably joined together here by various screw connections. The air guide housing 7 consists of bent and edged sheet metal sections, in order to guide the cooling air flow emerging from the cooler unit 5 on the air inlet side with the fewest possible losses to the cylinder 10a.

(11) FIG. 4 shows the opposite side of the crankcase 6 from that of FIG. 3, on which the second cylinder 10c of the low-pressure stage is arranged.

(12) Per FIG. 5, the assembled air guide housing 7 includes the first housing piece 7a and the second housing piece 7b, which are detachably joined together by screw connections. The cylinder 10a protrudes through a recess 13. The second housing piece 7b encloses the cylinder 10a substantially in a U-shape and in particular also underneath the onflow side, along an elongated transverse section 14.

(13) In FIG. 6, two mutually opposing and spaced apart fins 15a and 15b are arranged at the inside of the air guide housing 7, being arranged in the region of the cylinder 10a being cooled on the air guide housing 7. The two fins 15a and 15b serve to deflect the cooling air flow from the axial direction to the radial direction to cool the cylinder 10a. The radial cooling air guidance occurring in this region assumes the form of the axial fan 9 on the side with the compressor unit 1 and prevents a sideways outflow of the cooling air, which is thereby deflected in the direction toward the cylinders. The tub geometry of the air guide housing 7 takes the cooling air through the transverse section 14 underneath the cylinder 10a to the lower edge of the neighboring cylinder 10b, which is also secondarily cooled in this way.

(14) The alternative embodiment of an air guide housing 7 shown in FIG. 7 is an injection-molded plastic piece, on which the fins 15a and 15b are directly molded. Thanks to the transverse section 14, likewise molded on, cooling air is also taken underneath the cylinder to the neighboring cylinder so as to cool that as well.

(15) The invention is not limited to the above-described preferred sample embodiment. Instead, many modifications are conceivable that are also included in the protection scope of the following claims. Thus, for example, it is also possible to design a single-cylinder compressor unit with the external cooling air guidance according to the invention. The cooling air guidance is especially suitable for installing the compact-design piston compressor described here inside a box-shaped noise protection capsule, in order to accomplish a sufficient cooling of the piston compressor despite the soundproofing produced by the encapsulation.

(16) The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE SYMBOLS

(17) 1 compressor unit 2 first end face 3 motor unit 4 second end face 5 cooler unit 6 crankcase 7 air guide housing 8 crankshaft 9 axial fan wheel 10 cylinder 11 screw 12 screw 13 recess 14 transverse section 15 fin 16 axial fan wheel contact protection cover 17 noise protection capsule 18 rail vehicle